Jul 10, 2010

While too much cof­fee can cause health prob­lems, such as ul­cers, the new re­search sug­gests gen­er­ous amounts of it are most strongly linked to low­er can­cer rates—be­tween two and five cups dai­ly, or even more, de­pend­ing on the study and can­cer type.

While too much cof­fee can cause health prob­lems, such as ul­cers, new re­search sug­gests gen­er­ous amounts of it are most strongly linked to low­er can­cer rates—be­tween two and five cups dai­ly, or even more, de­pend­ing on the study and can­cer type. (Im­age cour­tesy one­mhz)

In one ana­lysis, re­search­ers pooled da­ta on reg­u­lar cof­fee drinkers and non-drinkers from nine stud­ies col­lect­ed by the In­terna­t­ional Head and Neck Can­cer Ep­i­de­mi­ology con­sor­ti­um.

Peo­ple who drank about four or more cups a day had a 39 per­cent de­creased risk of oral ca­vity and phar­ynx can­cers com­bined, the in­ves­ti­ga­tors found. Da­ta on de­caf­fein­at­ed cof­fee was too sparse for de­tailed anal­y­sis, they added, but in­di­cat­ed no in­creased risk. Tea in­take was­n’t as­so­ci­at­ed with head and neck can­cer risk.

“What makes our re­sults so un­ique is that we had a very large sam­ple size… we had more sta­tis­ti­cal pow­er to de­tect as­socia­t­ions be­tween can­cer and cof­fee,” said said lead re­searcher Mia Hashibe of the Uni­vers­ity of Utah.

The re­search is pub­lished in the ad­vance on­line is­sue of the journal Can­cer Ep­i­de­mi­ology, Biomark­ers & Pre­vention, pub­lished by the Amer­i­can As­socia­t­ion for Can­cer Re­search.

In an­oth­er stu­dy, pre­sented at the as­socia­t­ion’s Fron­tiers in Can­cer Pre­vention Re­search Con­fer­ence last De­cem­ber, Har­vard Uni­vers­ity re­search­ers pre­sented da­ta show­ing that men who drank the most cof­fee had an up to 60 per­cent de­creased risk of le­thal and ad­vanced pros­tate can­cers.

Re­sults of a third study pub­lished in the Jan­u­ary is­sue of the same jour­nal showed a de­creased risk of gli­o­mas, or brain tu­mors, as­so­ci­at­ed with cof­fee. This link was found among those who drank five or more cups of cof­fee or tea a day, ac­cord­ing the re­search­ers from Im­pe­ri­al Col­lege, Lon­don.

And yet a fourth stu­dy, in the April 2008 is­sue of Can­cer Ep­i­de­mi­ology, Biomark­ers & Pre­vention, found that at least two or three cups of coffee a day can ei­ther re­duce the risk of breast can­cer or de­lay its on­set.

This ef­fect is re­lat­ed to es­tro­gens, fe­male sex hor­mones, said the sci­en­tists, from Lund and Malmö uni­vers­i­ties in Swe­den. Cer­tain met­a­bol­ic prod­ucts of these hor­mones are known to be car­cin­o­gen­, and var­i­ous com­po­nents of cof­fee can al­ter the me­tab­o­lism so that a wom­an ac­quires a bet­ter con­figura­t­ion of var­i­ous es­tro­gens, in­ves­ti­ga­tors said. Caf­feine al­so ham­pers can­cer cell growth.

In the stu­dy, re­searcher Hel­e­na Jern­ström and col­leagues stud­ied the cof­fee-drink­ing habits of wom­en in­clud­ing nearly 460 breast can­cer pa­tients at Lund. Cof­fee’s ef­fect, the sci­en­tists said, var­ied de­pend­ing on which ver­sion wom­en have of a gene called CYP1A2, which pro­duces an en­zyme that breaks down es­tro­gen and cof­fee. Half of the wom­en had a var­i­ant called A/A, while the oth­ers had ei­ther A/C or C/C.

“Those wom­en who had one of the C var­i­ants, and who had drunk at least three cups of cof­fee a day, de­vel­oped breast can­cer con­sid­erably more sel­dom than wom­en with the A/A var­i­ant with the same cof­fee con­sump­tion. Their can­cer risk was only two thirds of that of the oth­er wom­en,” Jern­ström said.